NUTRITIONAL AND TOXICOLOGICAL STUDIES ON Periophthalmus koelreuteri FROM OKPOAMA-BRASS, BAYELSA STATE

Abstract

Mudskippers have been used extensively in ecotoxicological studies due to their tendency to bioaccumulate heavy metals and other environmental toxicants. The present study investigated the proximate, fatty acids, minerals and heavy metals composition of Periophthalmus koelreuteri (mudskipper) from Okpoama-Brass, Bayelsa State. Proximate composition was determined by AOAC methods, fatty acids composition was determined by gas chromatography and mineral/heavy metals were determined by atomic absorption spectrophotometry. Health risks associated with consumption of mudskippers (estimated daily intake-EDI, target hazard quotient-THQ and carcinogenic risk-CR) were determined by calculation. Proximate composition of samples were as follows: 52.50±0.20% crude protein, 7.50±0.02% crude fat, 0.29±0.01% carbohydrates, 15.71±0.015% crude fibre, 18.00±1.00% ash and 6.00±0.04% moisture. The following fatty acids were detected: lauric acid, palmitic acid, margaric acid, stearic acid, oleic acid, linoleic acid and arachidonic acid. Minerals detected includes Na, K, Ca, Mg, Fe, Zn, Cu, Co and Mo and heavy metals (Cd>Cr>Pb). Health risk assessment showed the following: EDI for Cd was 0.001 mg/100g-1bw/day; EDI for Cr in the samples was 0.000628mg/100g-1bw/day. THQ value for Cd was >1 hence consumption of mudskipper (with respect to Cd) is not advised as it may pose health threats to the consumers. THQ for Cr and Pb were <1 hence there are no health risks associated with respect to these metals. CR values for all heavy metals (Cd, Cr and Pb) in the sample were within the permissible limits. Mudskipper is a good source of protein, fatty acids and minerals however it accumulates toxic heavy metals from the environment.